How to Identify Fibers in Fabric

Author:: PGupta0919

What Are Fibers?

Fibers are the most basic units of textiles that we use in our day to day lives. Fibers are often either natural (derived from natural sources like plants) or man-made (or synthetic).

All fibers that exist today have different inherent properties which affect the fabric's hand or feel, weight, appearance, performance, etc.

Natural Fibers

Derived from natural sources, these fibers are obtained from different sources. Some of them are listed as follows.


Fiber Classification	Fiber Name
Cellulosic/Vegetable Fibers	Cotton, Hemp, Jute, Flax, Coir
Animal/Protein Fibers	Silk, Wool
Mineral Fibers	Asbestos

Man-Made Fibers

Man-Made Fibers are artificially prepared fibers. There are 3 major ways, either through melt spinning, dry spinning or wet spinning. Some of the man-made fibers are listed below.


Fiber Classification	Fiber Name
Cellulosic Fiber	Acetate, Rayon, Triacetate
Man-made/Synthetic Fiber	Acrylic, Modacrylic, Nylon, Olefin, Polyester, Spandex

Tests to Identify the Fibers

There are several ways to identify the fibers in the fabric. Some of them are:

Touch and feel of the fabric
Microscopic view of the fabric
Burning test
Solubility test

Touch and Feel

By feeling the fabric, the fiber in the fabric can be idenitfied. This often requires experience and skill but an estimate of what fiber may be present in the fabric can be made using this technique.

Microscopic View of the Fabric

Each fiber has a different cross-sectional and longitudinal view when it is viewed under a microscope. Through this technique, one can identify how the cross-sectional and longitudinal views are, and then compare with the actual cross-sectional and longitudinal views of the fibers to identify it. Under a microscope the shapes of the fibers are as follows.

Burning Test

This is perhaps the most commonly used method to identify fibers. This usually gives a more accurate result when the fabric is 100% composed of one particular type of fiber. If the fabric is composed of multiple fibers (example polycotton), this test may not give an accurate result, because the component fibers will behave differently.

To do a burning test, take out a couple of yarn strands out of the fabric and using a lighter, apply flame to the yarn strands. Take readings of your observation in relation to the result of the application of flame, the odor when the flame is applied, the characteristics of the flame such as color etc, and appearance of the residue.

The burning characteristics of different fibers are listed below. Compare your results with the table below to identify the fiber.


Fiber	Application of Flame	Odor	Characteristics of the Flame	Residue Appearance
Acetate	Burns quickly	Burnt wood/hot vinegar	Flame is unsteady and difficult to extinguish on blowing	Hard, irregular, black bead shaped
Acrylic	Burns rapidly and melts	Acidic smell	Smoky flame	Hard, irregular, black bead shaped
Cotton	Burns quickly	Burning paper	Burns rapidly with a yellow flame	Light grey to charcoal grey ash
Nylon	Burns slowly and melts	Burnt plastic	Self-extinguishes	Hard, grey bead appearance
Polyester	Burns slowly and melts	Sweet smell	Yellow/orange flame	Hard, black/brown bead appearance
Rayon	Burns quickly	Burning paper	Yellow flame	Light, grey ash
Silk	Burns slowly	Burning hair	Self-extinguishes	Black ash
Wool	Burns slowly	Burning hair	Self-extinguishes	Brittle, small black bead

Fiber Solubility Test

All fibers dissolve in a particular chemical solution. This method can be used to validate the presence of a particular type of fiber in a fabric. Some of the solubility test results are shown in the table below.


Fiber	Chemical
Acetate	Acetone
Acrylic	Dimethyl Formamide
Cotton	75% Sulphuric Acid
Nylon	90% Formic Acid
Polyester	m-Cresol
Silk	5% Sodium Hydroxide
Viscose	60% Sulphuric Acid
Wool	5% Sodium Hydroxide